docs: def _read_txt(self, stream):
          '''
          Load a PLY element from an ASCII-format PLY file.  The element
          may contain list properties.
  
          '''
          self._data = _np.empty(self.count, dtype=self.dtype())
  
          k = 0
          for line in _islice(iter(stream.readline, b''), self.count):
              fields = iter(line.strip().split())
              for prop in self.properties:
                  try:
                      self._data[prop.name][k] = prop._from_fields(fields)
                  except StopIteration:
                      raise PlyElementParseError("early end-of-line",
                                                 self, k, prop)
                  except ValueError:
                      raise PlyElementParseError("malformed input",
                                                 self, k, prop)
              try:
                  next(fields)
              except StopIteration:
                  pass
              else:
                  raise PlyElementParseError("expected end-of-line",
                                             self, k)
              k += 1
  
          if k < self.count:
              del self._data
              raise PlyElementParseError("early end-of-file", self, k)